1. Field of the Invention
The present invention relates generally to a foot switch device used for activating a dental or medical treatment apparatus. More particularly, the invention relates to a two-stage foot switch device having an upper moveable cover. An operator depresses the cover with his or her foot to activate the switching mechanism in the foot switch device. The switching mechanism controls the operation of the dental/medical apparatus. The foot switch device is particularly suitable for operating an ultrasonic dental scaler.
2. Brief Description of the Related Art
Today, dental and medical professionals use many instruments that are controlled by foot control systems. For example, surgical cutting instruments, endoscopic tools, irrigation and aspiration tools, dental drills and other handpieces, ultrasonic dental scalers, and dental prophylaxis units can be activated with foot control systems. The foot control system typically includes a foot switch device that is placed on the floor within easy reach of the practitioner. The foot switch is used to activate a dental/medical apparatus, which includes a base-operating unit. The foot switch is typically connected to the base unit by a connector cable in a “hard-wired” system. Alternatively, remote, “wireless” foot control systems, which do not use a connector cable, can be used to activate the base unit in some instances. A flexible, instrument cable connects the dental/medical instrument, for example, a dental handpiece, to the base unit. The dental or medical practitioner activates the base unit and attached dental/medical instrument by depressing the foot switch with his or her foot. Some conventional foot switches are referred to as multi-position or multi-staged switches. An operator depresses the pedal of the foot switch to a certain position, and this action causes the dental/medical apparatus to operate in a specific mode. The particular operational mode is based on the position of the foot switch pedal. For example, with a two-position foot switch, a dental practitioner can depress the pedal to a first position so that water flows through the handpiece for rinsing the teeth of a patient. Then, the pedal of the foot switch can be depressed to a second position so that a cleaning spray flows through the handpiece for cleaning the teeth. Such foot control systems provide several advantages.
First, the foot switch device is easy to use and efficient. The dental/medical professional can activate the instrument attached to the base unit by simply depressing the foot switch with his or her foot. Secondly, the dental/medical practitioner's hands are kept free when working with a foot switch device. The practitioner thus can handle other instruments and accessories while treating the patient. The practitioner is better able to concentrate on performing the needed dental/medical procedure. Thirdly, as mentioned above, some conventional foot switches are used in wireless systems, which do not run a connector cable between the foot switch and base unit. These wireless foot switches are used to remotely activate the base unit and attached dental/medical instruments. Many dental/medical operatory rooms contain numerous long cords, cables, wires, and the like which can become entangled easily. The entangled cords and cables take up space and may cause potential safety hazards. A wireless foot switch system helps minimize some of these hazards.
Foot switch devices can have a wide variety of structures. For example, Bresnahan et al., U.S. Pat. No. 4,041,609 discloses a foot control unit for controlling the operation of dental equipment, particularly air turbine dental handpieces. The foot control unit includes a triangular-shaped base, a body portion that is supported by the base, and a removable cover. Three pivotal pedals project radially from the body portion of the foot switch in the form of a spider-like configuration. The pedals are arranged at evenly spaced positions around the circumference of the base. Each pedal includes a foot-engageable shoe connected to a pedal support member. A dentist may depress any of the pedals, and this action is transmitted to an actuator member, which also has a three arm spider-like configuration. The actuator causes a vertically movable plunger to be depressed and a control unit in the foot switch is activated. An electrical cable extending from the foot control unit to the dental handpiece is used to transmit the switching signal.
Jones et al., U.S. Pat. No. 4,114,275 discloses a foot switch for controlling the flow of compressed air to an air-driven dental handpiece. The foot switch device includes a diaphragm therein for forming an air-sealed chamber, which reduces in volume upon depression of the foot pedal. As the foot pedal is depressed, air is conveyed through an air tube to an air modulating, regulator valve that is positioned away from the foot pedal device. The valve controls the flow of compressed air to the dental handpiece and drives the dental handpiece. Alternatively, the system can include a diaphragm-operated electrical switch that is positioned away from the foot switch for electronically controlling the flow of air to the handpiece.
Matsui, U.S. Pat. No. 4,417,875 discloses a foot controller for controlling the rotational speed of an air turbine dental handpiece. The foot controller is designed such that the front part of the pedal is used for controlling high-speed rotation of the handpiece and requires a relatively small amount of foot pressure, while the rear portion of the pedal is used for controlling low-speed rotation and requires a relatively high amount of foot pressure.
Lee, U.S. Pat. No. 5,132,498 discloses a foot switch comprising a base covered with an upper cover and a press member. The foot switch houses a pressure-contact switch, a pivoting rotary-type actuating member, and compression spring. The press member is pressed down in response to a foot-pressing action. This causes the actuating member to rotate downward so that a hooked portion of the actuating member is pressed against a cylindrical press button, thereby activating the foot switch.
Warrin et al., U.S. Pat. Nos. 5,125,837 and 5,419,703 disclose an ultrasonic dental scaler unit having a handpiece and scaling insert that can be used for scaling teeth and providing therapeutic lavage solutions to periodontal pockets in the mouth. The dental scaler unit includes a foot switch device, which is connected to the base unit by an electrical cable. The scaler unit further includes a dental handpiece, which is connected to the base unit by a conduit containing electrical wires and a tube for cooling water. The base unit includes a switch that can be thrown to a first or second position. The foot switch also can be depressed to a first or second position. The positions of the base unit switch and foot switch make it possible for the practitioner to use the apparatus for scaling only, lavage only, or simultaneous lavage and scaling.
Jovanovic et al., U.S. Pat. No. 5,754,016 discloses an ultrasonic dental scaler system having a base unit, which is connected by a cable to a foot switch device. The scaler handpiece, which is connected to the base unit, includes a feedback coil for controlling the amplitude and vibration of the magnetostrictive scaling insert. The amplitude and frequency of vibration of the tip of the scaling insert can be continuously adjusted to maintain constant scaling power. The foot switch device is connected to a boost enabler in the base unit by a connector cable. The foot switch can include first and second electrical contact positions, where the second position provides a temporary boost in power to the handpiece.
Beerstecher, U.S. Pat. No. 6,866,507 discloses a foot switch device for controlling the operation of a dental apparatus having a multifunctional handpiece. The foot switch device includes a base plate and a relatively movable cover plate. A space between the base plate and cover plate forms a fluid tight hollow cavity. Multiple press switches are arranged in the hollow cavity. The press switches are made from a printed circuitry, which is sandwiched between first and second carrier foils. A signaling line connects the foot switch device to the electronic control systems of the dental apparatus.
Feine, U.S. Pat. No. 6,893,261 discloses a foot switch for controlling an ultrasonic dental scaler. The foot switch incorporates the circuitry for controlling the vibrational frequency of the scaling insert and can also provide water and light to a remote head unit. A cable bundle connects the foot switch to the remote head. The foot switch housing is connected to a power supply and is additionally connected to a water source. The foot switch housing can also include a light source such as an argon lamp. The remote head can be attached to a dental treatment chair or it may be carried on the belt of a dentist or dental hygienist.
Conventional foot switches are generally effective; however, there is a need for an improved foot switch device. For example, some conventional foot switches have a relatively high, pointed cover that is mounted over the foot switch base. Consequently, an operator may feel an uncomfortable sensation while pressing the cover with his or her foot. It thus would be desirable to have a foot switch that includes a relatively flat cover with a comfortable foot-engaging surface. The foot switch should be durable and lightweight. The foot switch should also have good dimensional stability so that it cannot be tipped over easily. Furthermore, the foot switch should be capable of being activated by depressing the upper cover at any point along its perimeter. In other words, the foot switch should have a full three hundred and sixty-degree (360°) level of perimeter activation. Additionally, it would be desirable to have a foot switch that could be used to activate a dental/medical unit in a hard-wired or wireless system. The present invention provides such a foot switch having these objects, features, and advantages as well as others.